X-ray unit



Jap. 4, 1949. B. F. wEHMER l 2,457,961

X-RAY UNIT Filedsept. 2e, 1946 2 sheets-sheet 1 NVENTOR E BRUNO F. WEHMER ATTORNEY Jan. 4,51949. B. F. WEHMER 2,457,961

l x-RAY UNIT Filed sept. 26, 194e 2 sheets-sheet 2 FIG. 4 26 24 l vw Ism-

INVENTOR BRUNO F. WEHMER ATTORNEY Patented Jan. 4, 1949 Bruno F. Wehmer, `Melrose Park, Ill., assgnor to The Wm. Meyer Company, Chicago, Ill., a cori poration of Illinois Application September 26, 1946, Serial No.` 699,534 i This `invention relates to Xeray units, and more particularly to such units wherein an efflcient cooling system is provided for effectively increasing the usable time of a given size of unit.

It is a general object of my present invention to provide an eifective and efcient cooling system for an X-ray unit in which the high voltage parts, including the X-ray tube and high voltage transformer, are mounted within a unitary structure. 4

As another and more specific object, my invention contemplatesthe provision of a unitary structure and arrangement of parts of an X-ray unit wherein the parts are effectively and `erliciently cooled and the arrangement effects the cooling of said parts in relation to the heat emitted thereby and their temperature requirements for continued operation.

A further' object of the invention is to provide a single forced-feed system for cooling the high voltage heat-generating parts of an X-ray unit in a manner such that the said high Voltage parts may be grouped together and protected to limit danger and so that parts of a given size may be used longer at one time or for a higher percentage of the time without damage thereto.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings in which similar characters of reference indicate similar parts throughout the several views.

Referring to the drawings of which there are two sheets,

Fig. 1 is a front elevational view of an X-ray unit of the type disclosed asa preferred embodiment of my present invention and wherein one type of support for the unit is indicated in dot and dash lines;

Fig. 2 is a side View of an X-ray unit embodying a preferred form of my present invention and wherein the housing is shown `in `section to illustrate features of the internal structure and arrangement of the unit;

Figs. 3 X-ray unit shown in Fig.` 2, wherein the sections are taken substantially on lines 3-3 and 4-4 respectively, of Fig. 2; and

Fig. 5 is a top sectional View of one preferred form of part utilized in the X-ray unit shown in Figs. l to 4, inclusive.

In the exemplary embodiment of my invention which is disclosed in the accompanying drawings for illustrative purposes, transformers IIJ and I2 are carried by support brackets I3 and mounted within a housing I4 nearf an X-ray tube I5. Byf

and Li are rear sectional viewsof the` 2 claims.` (o1. 25o- 89) mounting the transformers in closely spaced relationship to the X-ray tube and within a closed housing, two purposes are served; namely, (a) y the high voltage winding of the transformer and the leads extending from that winding to the X-ray tube are safely confined within a substantiallprotective enclosure; and (b) the transformers and the X-ray tube may be readilyimmersed for operation in a bath of an electrical insulating cooling liquid, such as a dehydrated oil.

`On the other hand, a considerable amount of energy utilized in an X-ray tube is dissipated in the form of heat; Since the transformers must be operated without having their windings overheated, the close confinement of both the X-ra'y tube and the transformers within a closely confined space and cooled by the same liquid coolant has a tendency to limit the time during which the X-ray unit may be continuously operated, as well as the `percentage of the time during which it may be operated intermittently.

With the foregoing factors in mind, I have provided an auxiliary cooling system and an arrangement of parts which do not materially detract from the expressed advantages of the unitary structure, but which very materially increase the length of `time during which an X-ray.

the housing I4 includes a main portion IS comprising a sheet metal container I 1, one end "of which is closed by a channel I8 of insulating material, such as phenol fiber. Desirably, the open end of the metal container II has internal edge flanges I 9 to which the panel I8 is securedhby removable fastening means, such as a plurality of screws 20 so as to form a `iiuid-tightjoint.`

Within the main housing portion I6, a pair of support brackets I3 are secured to the panel I8 and carry the transformers ID and I2. The transformer I0 has a laminated iron core 22, the opposite ends `ofwhich are clamped to one side of the support brackets I3 by metal clamping strips 23; said lclamping strips being secured to the support brackets by fastening means, such as screws 24 and 25. lOn one leg of the core 22 and disposed intermediate the support brackets I3, the transformer I0 has a primary winding 26 and a high Voltage secondary winding 21. 'I'he high voltage secondary winding 21 provides the anode poten, tial forfthe operation of the X-ray tube.

The transformer I2 has a laminated ironcore 28 secured at one end to one of the support brackets I3 by a `clamping strip 29 which is secured in place by fastening means, such as screws 30' and 32. On one leg of the core 28, the transformer I2 has a primary winding 33 and a low voltage secondary winding 34, which low Voltage secondary winding provides the heating current' for the filament of the X-ray tube.

Also, within the main housing portion I6, near the transformers Ill and l2 and adjacent the panel I 8, the K-ray tube is carried by suitable outside the housing through a passage 3B in a supporting element comprising a cap screw 3i). The Sylphon type bellows is, of course, hermetically sealed with respect to the interior of the main housing portion i6.

In order to reduce the material through which the X-rays are emitted from the unit, a portion of the panel I8 is recessed, as indicated at 40 adjacent the anode of the X-ray tube. Also, in use, rthe panel end of the X-ray unit is desirably covered with a cap ft2, as shown in Fig. 1. Furthermore, supporting adapters 43 are secured to opposite end walls of the main housing portion I@ for hingedly supporting the unit relative to a suitable support bracket, such as 44, as shown in Fig. l.

At a convenient position and desirably secured to one side of the main housing portion I6 in order to preserve the unitary structure of the X-ray unit as a whole, is an auxiliary housing portion 45, which housing portion is preferably of sheet metal construction and sealed so as to be fluidtight. In my preferred construction, two communicating passages are provided for connecting the interior of the main housing portion i6 to the interior of the auxiliary housing portion 45.

One of the passages is desirably at one end of the main housing portion I5 near the high voltage winding 21 of the transformer and is provided by a metal tube 46. AAt the other end of the housing and preferably near the X-ray tube or its heat-radiating iins, the housing portions are connected through aligned openings 41 and 48. By preference, a tube 49 is mounted in said aligned openinges and extends toward the X-ray tube or its cooling fins to serve as a baffle whichdirects uid flow across the X-ray tube or its cooling fins.

Together the main and auxiliary housing portions V`form a hermetically sealed container for the X-ray unit and its cooling system, which con. tainer is lled completely with a liquid, such as dehydrated oil, which liquid is an electrical .insulator and is adapted by circulation to carry heat away from the heated parts of the unit.

Within vthe auxiliary housing portion 45, a motor 5B is supported by* a suitable bracket, suchy as 52, and is so disposed that an impeller 5.53`

mounted on the motor shaft 54 is ina position for circulating the liquid within the housing kthrough the tube 46 Viromthe auxiliary-,housing portion and into the main housing portion toward the, high voltage winding of the transformer. I prefer to mount the impeller 53 within or closely adjacent the tube 46 to improve its pumping action. Between the motor 5|] and the passage propided by the aligned openings 41 and 48, a cooling radiator 55 is supported within the auxiliary housing portion 45 to cool the liquid as it passes through the auxiliary `housing portion from one passage to the other under the force imparted thereto by the impeller and its driving motor.

Although there are various types of radiators which might be utilized for effecting the cooling of the liquid as it passes through the auxiliary housing portion, I have selected, in the present instance, a radiator composed of relatively flat tubular material 56 formed in a zigzag pattern, as shown in Fig. 5, in order to present a large f outer surface area across which the liquid may pass for cooling without unduly obstructing the 'ow of the liquidthrough the auxiliary housing portion. At opposite ends the tubular material of the vcooling radiator is providedwith iittings 51 which extend through opposite walls of the lauxiliary housing portion to support the radiator and pro-vide connections for the flow of a coolant, such as water, through the interior of the radiator.

Since the transformers normally dissipate less heat than the X-ray tube and should be kept relatively cool for eiiicient and elective operation, I have so designed and arranged my X-ray unit and its associated cooling system that the heated liquidkfrom the X-ray tube flows into the auxiliary housing portion and across the radiator for cooling. 'I'he cooled liquid is forced back into the main housing portion to cool the transformers before it again reaches the vicinity of the X-ray tube.

In order to compensate for variations in pressure within the housing which result from temperature variations, the expansion-compensating bellows 31 provides an expansible and contractible sealed element within the housing which is exposed interiorly to atmospheric pressure.

While I have illustrated a preferred embodi ment of my invention, many modificati-ons may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims. Y

Having thus described my invention, what I claim as new and desirer to secure by Letters Patent of the United States is:

l. AnX-ray unit comprising, in combination, an X-ray tube, transformer means having high and low voltage windings for providing operating potentials to said tube, said X-ray tube having cooling fins thereon, a main housing for said X- r'ay tube and transformer means, said main housing having a Sylphon type expansion-compensating bellows thereinrincluding means providing a passage communicating with external atmospheric pressure, van auxiliary housing on one side of the main housing and provided with two ilu-icl flow passages communicating with the main housing, one of said fluid ilowpassa'ges being adjacent the cooling fins on the X-ray tube and the other being adjacent the high voltage winding of the transformer means, said main and auxiliary housings together providing a liquid-tight con tainer and being substantially filed with an electrical insulating heat-conveying liquid, a cooling radiator mounted in said auxiliary housing and having connections for the flow of coolant there through, and electrically driven impeller means mounted in said auxiliary housing for eilectlng flow of said heat-conveying liquid from the main housing through the passage adjacent the cooling ns and into the main housing through the passage adjacent the high voltage winding of the transformer means so that said cooling radiator cools the heat-conveying liquid intermediate said passages in said auxiliary housing.

2. An X-ray unit comprising, in combination, an X-ray tube, transformer means having high and low Voltage windings for providing operating potentials to said tube, said X-ray tube having cooling fins thereon, a main housing for said X- ray tube and transformer means, an auxiliary housing on one side of the main housing and provided with two fluid flow passages communicating with the main housing, one of said fluid flow passages being adjacent the cooling fins on the X ray tube and the other being adjacent the high voltage winding of the transformer means, said main and auxiliary housings together providing a liquid-tight container and being substantially lled with an electrical insulating heat-conveying liquid, a cooling radiator mounted in said auxiliary housing and having connections for the flow of coolant therethrough, and electrically driven impeller means mounted in said auxiliary hous- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,992,335 Tietig Feb. 26, 1935 2,121,630 Gross et al June 21, 1938 2,179,933 Werner Aug. 29,4 1939 2,259,037 Graves Oct. 14 1941 2,353,720 Goldeld Feb. 23, 1942 OTHER REFERENCES General Elec. Review, vol. 28, No, 3, Mar. 1925- Oil I'mmersed X-ray Generating Outfits and TheirUses, by Dr. W. D. Coolidge-Research Laboratory, General ElectricCo. (pages 182 to 192).' Copy in Div. 54. 

